Capitalizing on a 25-year relationship, Lull and Ament worked together closely to create the signature model bass. The bass features a 20% oversized body, but thinner body thickness than standard Mike Lull T4 models, along with a reverse headstock. Jeff Ament personally chose all custom colors, finish, and wood configurations. The JAXT4 comes with a chromed aluminum JA pickguard engraved with an Ament designed T-bass logo, Jeff’s signature on the headstock along with a special Mike Lull logo designed by Jeff to be used only on his signature model. Included is a custom Ament hardshell case with a hand-stenciled logo on the exterior, along with a bag of assorted Ament custom guitar picks.